TaeYong Woo+, A.S. Tayerani Charmchi+, Pouya Ifaei+, SungKu Heo, KiJeon Nam, ChangKyoo Yoo*, Three energy self-sufficient networks of wastewater treatment plants developed by nonlinear bi-level optimization models in Jeju Island, Journal of Cleaner Production (ISSN:0959-6526, SCIE, Top 10% journal:Engineering Civil), Elsevier, 379(11), pp.134465 (2022.11) (Acknow: NRF2021 & CC graduate school & Brain Pool Program)